If you breed rodents you are bound to get attached to some. My daughter breeds naked rats (the kind with patchy fuzz). The male she uses is my pet (Jack) and she is selling the first litter off with the exception of one girl so she can expand! Also we had a feeder breeder rat born and it looks like mothers playing tug a war took one of his hind legs by accident, my wife adopted him (Lego). We also name the boys we use for breeding since their are only 4 and they will be around for a while (Ronin, Daniel, Sheppard, and Rodney).
Here is a picture of a naked rat at 3 1/2 weeks. The fuzz keeps falling off and getting less and less.
And here is a picture of Lego when he before he became a fat overweight boy. This is the side he is missing his hind leg on. It doesn't seem to slow him down though!